Answer
$$b=\frac{A}{h}.$$
Work Step by Step
To solve the given equation for $b$, we divide both sides by $h$ as follows
$$\frac{A}{h}=\frac{hb}{h}\Longrightarrow b=\frac{A}{h}.$$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.